When you keep fish at home, you commit to creating a world that provides all their needs — including mental ones. There’s little doubt that fish, like other creatures, are stressed by monotony.

First, know your fishes’ needs. For example, fish that naturally live on reefs feel safest near steep walls, while others might take to open space. Water flow preferences are also species-specific. Take beta fish, which have large, delicate fins designed for calm, shallow ponds. Even barely detectable currents stress them out. But for fish who prefer going with the flow, sporadically redirecting water motion might make their day.

Remember, anything in a tank can provide enrichment. Many needs are served by varied sizes, colors and textures of substrate (the material used on the tank bottoms), while fixtures like PVC pipes, treasure chests and plants form great hiding spots.